A heat treatment for a nickel-base alloy is described in U.S. Pat. No. 3,536,542 to Murphy et al. The heat treatment comprises heating the alloy to a temperature of about 2100.degree. F. to about 2200.degree. F. for 2 to 8 hours. This heating is followed by fast cooling, and then treating at a temperature of about 1975.degree. F. for about 2 to 8 hours. Again the alloy is fast cooled and then treated at a temperature of about 1700.degree. F. from 12 to 48 hours. This is followed by fast cooling and treating at a temperature of about 1400.degree. F. from 8 to 25 hours. The alloy is then fast cooled.
U.S. Pat. No. 4,161,412 to Henry discloses a method of heat treating a gamma/gamma-prime-alpha eutectic nickel-base superalloy by heating the alloy to a temperature at which at least a portion of the gamma-prime phase will transform to a gamma-phase. The resulting heated body is maintained at this temperature to facilitate the transformation of at least a portion of the gamma-prime phase to a gamma-phase. The resulting transformed body is cooled to a temperature at which at least a portion of the gamma-phase precipitates to a modified gamma-prime phase.
U.S. Pat. No. 3,272,666 to Symonds discloses a method of heat treating nickel-base alloy articles which comprises heating the alloy over a period of not more than 70 seconds nor less than 15 seconds to a temperature in the range from 1975.degree. F. to 2200.degree. F. for a sufficient time to effect solution of the gamma-prime phase. After rapid cooling, the alloy may be rolled, drawn, or otherwise fabricated and then age hardened by prior art methods.
U.S. Pat. No. 2,570,194 to Bieber et al describes a high temperature treating sequence for nickel alloys comprising heating the alloy within a range of about 1950.degree. F. to 2200.degree. F. for at least 1 hour and up to 24 hours or more. This is followed by sufficiently rapid cooling to preserve the solid solution of the age hardening precipitable phases. The alloy may be rapidly cooled by quenching in oil or water, and the alloys are then aged at 1300.degree. to 1500.degree. F. for at least 4 hours and up to 24 hours or more.